Sunday, October 31, 2021

Picture of the Day: Konza Prairie in Autumn

 Image courtesy of Jill Knutson Haukos

The Konza Prairie Biological Station is a protected area of native tallgrass prairie in the Flint Hills of northeastern Kansas. "Konza" is an alternative name for the Kansa or Kaw Indians who inhabited this area until the mid-19th century. The Konza Prairie is owned by The Nature Conservancy and Kansas State University.

For more information on this beautiful Tall Grass Prairie, click here.

For information on visiting, click here.

Friday, October 29, 2021

Why aren't there more grass plant nerds?

Schizachyrium scoparium inflorescence

 I am a plant nerd.

At various times in my life I have become obsessed with different plant groups, whether aroids, or banyan trees, or palm trees, or even the occasional foray into orchids. In that long time span I have become familiar with my fellow plant nerds, and the reasons why they have become enamored of their chosen plant group. Most are gardeners and collectors, and love to grow and take care of the plants; some are researchers, and some have even taken their passion and created a business out of it.

The reasons why they focus on a particular plant group are also varied. Perhaps the plants have gorgeous and strange flowers like orchids, or amazing leaves and inflorescences like the aroids. Perhaps the plants remind them of exotic things, like palm trees, or perhaps they are rare and thus of much value.

Grasses as a whole don't seem to normally engender such feelings among plant nerds, with the possible exception of bamboos. Poaceae flowers are usually minute things, and their leaves are relatively similar within the family. Grasses are not rare, and in fact are so successful and abundant that they have become an unremarked part of our environment. People collect and grow aroids and orchids in pots and their gardens, but it's unlikely that plant nerds would keep potted grasses (though I have kept a potted Japanese Blood Grass, a nerdy act if there ever was one!). The fact that they are relatively hard to identity to species also scares off a lot of people.

And yet within the grass family there are remarkable species that are worthy of being the focus of plant nerds. Grasses that have wonderfully fascinating adaptations or are rare and endemic. Grasses like Swallenia alexandrae, the Eureka Dune Grass, which is only found in a few isolated dunes in the vast barren wastelands of Death Valley in California; or the beautiful vining bamboo Chusquea delicatula, found only in the highlands near the ancient Incan city of Machu Picchu; or even the strange and oil-exuding Orcuttia grasses that live in transient vernal pools and don't seem to have any affinity at all with other extant grass species. These and others will be some of the species I hope to feature in my future posts, and which I hope to encounter in situ going forwards.   

Spider on Cenchrus purpureus

Tuesday, October 26, 2021

The Fight to Create a New Paradigm of Old Growth Grasslands


An updated version of this post is in the Missouri Prairie Journal (pdf)

The recent fight to save a remnant Prairie called Bell Bowl Prairie in Illinois has driven home (again) the precarious state of the world's ancient and pristine grasslands.

One major factor in the lack of focus about the dangers to this biome (as opposed to, for example, the rainforests) is the fact that many people still cling to the view that grasslands are simply a transitional or 'arrested' state towards becoming a forest. The belief that grasslands are low diversity, degraded land that had once been forests, or are "empty" land that could be used for something better, is one that has repeatedly been used to justify the destruction of this biome in history.

However, there has been a recent push by grassland researchers and proponents to combat this perception by pushing the notion of the so-called "Old Growth Grasslands", which is comparable to the traditional "Old Growth Forests".

What are Old Growth Grasslands?

The term Old Growth Grasslands (OGG) is relatively new, and refers specifically to grasslands that are characterized by having:
  • Ancient history and heritage, as opposed to being so-called secondary grasslands that just recently arose from human degraded forest or other land. For example, the plant lineages making up the Cerrado in South America started assembling almost 10 million years ago, long before our species even evolved.
  • High biodiversity compared to secondary grasslands. In fact, some old growth grasslands boast the highest plant species diversity in the world.
  • Very slow rate of recovery when destroyed due to agriculture, plantation forestry, and other human activities.  An Old Growth Grassland may take centuries and even millennia (projected 1400 years!) to recover its former species richness when it has been degraded to secondary grassland.
The term '"Old Growth" is made synonymous with words like ancient, intact, native, natural, pristine, reference, remnant, semi-natural, and undisturbed.

What is the problem?

There is a widespread perception among people that grasslands (including OGG) are simply degraded forests whose successional development has been arrested by disturbances such as fire and herbivory. 

Policies to combat climate change and protect biodiversity have often ignored the protection of these ancient grasslands, and in many cases have actually caused their destruction via deliberate tree-planting on pristine grasslands (afforestation)

What is the goal?

We must help change the widespread perception that old growth grasslands are simply degraded forested areas and a mere transitional stage towards becoming forests. This change in viewpoint will hopefully give this ancient biome a value and protection equal to rainforests and other old growth forests.

What is happening to Old Growth Grasslands?

The old growth grasslands have been and are still one of the most threatened ecosystems in the world, and in fact we have lost and are losing ancient grasslands at a pace that is significantly more rapid than loss of forests.

A few examples:

The majority of old growth grasslands in the USA has been lost, and only isolated remnants remain. For example, up to 99% of all Tall Grass Prairies in the country is gone, and only isolated remnants remain. Other grassland types are not faring well either. In one year alone (2018-2019), the Great Plains lost 1.1 million hectares, which is an area greater than Yellowstone National Park.

Half of the Brazilian Cerrado has already been cleared for agriculture expansion, and up to a million hectares is cleared each year. This is the equivalent of wiping out an area the size of New York City every month!

More than half the Pampas of South America have been lost to agriculture and cattle breeding. The remaining 50 million hectares of these grasslands are still being decimated, and are home to 540 recorded wild bird species, 12 of which are globally threatened.

The recent trend of planting trees to combat climate change has also caused widespread problems, when trees (and especially weedy invasive species) are planted in pristine grasslands ("afforestation") instead of degraded areas. 

Why must we fight for Old Growth Grasslands?

1. The old growth grasslands are the most biodiverse environments in the world at many scales.

For example, a mountain grassland in Argentina had an absolutely amazing 89 vascular plant species packed into a single square meter, a more diverse plant assemblage than one can see even in rainforests. 

Old growth grasslands are also significantly more diverse than secondary grasslands, having around 37% more species on the whole. When this diversity is degraded, it takes centuries or millennia (projected)  for the OGG to reassemble as diverse a community.

2. Old growth grasslands provide a home for innumerable species of animals. The destruction of old growth grasslands affects all the animals that depend on this habitat. 

For example, the total population of grassland birds in North America has dropped an astonishing 40% since 1966. One-third of all grassland bird species are on the Watch List due to steeply declining populations and threats to habitat. Birds that breed in the Great Plains of Canada and the U.S. and winter in Mexico’s Chihuahuan grasslands are experiencing exceptionally steep declines, a nearly 70% loss since 1970. Other temperate grassland birds have declined by 33% in that time.

Old growth grasslands also support numerous rare and endemic species. For example, the savannas of the South American Cerrado support 4,800 endemic plant and vertebrate species, all of which could be threatened by the continued decimation of this biome.

3. Grasslands play an essential role in combatting climate change. 

Grasslands store approximately 34 percent of the global stock of carbon in terrestrial ecosystems while forests store approximately 39 percent and agroecosystems approximately 17 percent. 

Some studies have shown that grasslands are an even more reliable carbon sink than forests, and although grasses account for only 3% of plant species on Earth, grass-dominated landscapes contribute 33% of global primary productivity, the amount of CO2 removed from the atmosphere every year to fuel photosynthesis.

4. Grasslands collect freshwater for most of the largest rivers of the world. 

For example, the Cerrado in Brazil delivers 40% of all the freshwater in that country! 

5. Possible conversion to secondary grasslands.

The loss of old growth grasslands due to conversion to human agricultural use or due to misguided attempts at afforestation frequently results in the rise of secondary grasslands in their place. Such secondary grasslands are less diverse and usually very fire prone (which creates new dangers to human communities and forests). For example, one major factor in the recent huge and destructive fires in the West Coast of the USA is the proliferation of invasive annual grasses, which have supplanted the perennial grasses and shrubs after degradation of the land due to over-grazing.

What can you do?

Champion and spread the concept of Ancient or Old Growth Grasslands, which are separate from secondary grasslands, and are equally as old and biodiverse and worthy of protection as Old Growth Forests.

References

Bardgett, R.D., Bullock, J.M., Lavorel, S. et al. Combatting global grassland degradation. Nat Rev Earth Environ 2, 720–735 (2021). https://doi.org/10.1038/s43017-021-00207-2

Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N., Rodenbeck, C., Arain, M. A., Baldocchi, D., Bonan, G. B., Bondeau, A., Cescatti, A., Lasslop, G., Lindroth, A., Lomas, M., Luyssaert, S., Margolis, H., Oleson, K. W., Roupsard, O., Veenendaal, E., Viovy, N., Williams, C., Woodward, F. I. & Papale, D. (2010). Terrestrial gross carbon dioxide uptake: global distribution and covariation with climate. Science 329,
834–838

Colli, G.R., Vieira, C.R. & Dianese, J.C. Biodiversity and conservation of the Cerrado: recent advances and old challenges. Biodivers Conserv 29, 1465–1475 (2020). https://doi.org/10.1007/s10531-020-01967-x

Comer, P. J., J. C. Hak, K. Kindscher, E. Muldavin, and J. Singhurst (2018). Continent-Scale Landscape Conservation Design for Temperate Grasslands of the Great Plains and Chihuahuan Desert. Natural Areas Journal 38:196–211.

Dass Pawlok, Benjamin Z Houlton, Yingping Wang, David Warlind. Grasslands may be more reliable carbon sinks than forests in California. Environmental Research Letters, 2018; 13 (7): 074027 DOI: 10.1088/1748-9326/aacb39

Intergovernmental Panel on Climate Change (IPCC), August 2019. The Special Report on Climate Change and Land (SRCCL), a special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.

Murray S, M. Rohweder, R. White (2000). Pilot Analysis of Global Ecosystems : Grasslands Ecosystems.

Nerlekar, Ashish & Veldman, Joseph. (2020). High plant diversity and slow assembly of old-growth grasslands. Proceedings of the National Academy of Sciences. 117. 201922266. 10.1073/pnas.1922266117. 

Simon Marcelo F., Rosaura Grether, Luciano P. de Queiroz, Cynthia Skema, R. Toby Pennington, Colin E. Hughes (2009). Recent assembly of the Cerrado, a neotropical plant diversity hotspot, by in situ evolution of adaptations to fire. Proceedings of the National Academy of Sciences Dec 2009, 106 (48) 20359-20364; DOI: 10.1073/pnas.0903410106

Veldman, Joseph W. “Clarifying the confusion: old-growth savannahs and tropical ecosystem degradation.” Philosophical transactions of the Royal Society of London. Series B, Biological sciences vol. 371,1703 (2016): 20150306. doi:10.1098/rstb.2015.0306

Wilsey, CB, J Grand, J Wu, N Michel, J Grogan-Brown, B Trusty (2019). North American Grasslands. National Audubon Society, New York, New York, USA

Wilson, J. Bastow; Peet, Robert K.; Dengler, Jürgen; Pärtel, Meelis (1 August 2012). "Plant species richness: the world records". Journal of Vegetation Science. 23 (4): 796–802.

World Wildlife Fun. (2021).  PlowPrint Report 2021

Thursday, October 21, 2021

Exploring the Layered Series of Grasses in an Island

Image 1. Ammophila breviligulata in center

Assateague Island straddles both Maryland and Virginia. It is a narrow barrier island that I visited and hiked this month, and it contains several ecological areas that made it quite diverse when it came to species diversity. Click here to look at a map of the island.

While I was there it came to me that the distribution of the grass species could be described as a series of layers. The major species were different as one went inward from the beaches to the marshes, and then to the drier meadows, and it was quite interesting to see how the species changed  as one hiked inward from the beach dunes.

Image 2. Panicum amarum

In the first and outer layer (the beaches), the two main grasses were Ammophila breviligulata and Panicum amarum. Both are dune building species, and A. breviligulata especially is crucial in creating the huge dunes that protect beaches. It is the dominant dune grass along the northeast coast, and I was familiar with it from my trips to the beaches in New Jersey. 

The two species are also easy to tell apart, with A. ammophila having very thin leaves, while P. amarum has much wider and bluish green leaves. You can clearly see this in Image 3 below.

Image 3. Ammophila breviligulata (left) and Panicum amarum (right)

Their inflorescences are very different as well, as you can see in Image 4 below. A. breviligulata has a whitish spike like inflorescence, while P. amarum has the typical Panicum type spikelets,

Image 4. Ammophila breviligulata (left) and Panicum amarum (right)

As I continued hiking inland into the marshes I came upon the second layer, which is actually composed of several sublayers (see Image 5 below). The area of the marsh closest to the sea (the low marsh) is inundated daily and has higher salt concentrations, and this area was dominated by Sporobolus alterniflorus (Spartina alterniflora). The so-called "high marsh" is farther away, is not inundated all the time, and is less salty. Here I found Sporobolus pumilus (Spartina patens) and the graminoid Juncus roemerianus, which is in the rush plant family and is NOT a grass. 

Image 5. Marsh

It was fairly easy to tell the two grass species apart. S. pumilus has wavy looking blades that look quite beautiful and distinctive. In the image below (Image 6) the species looks almost like a nice soft fluffy lawn.

Image 6. Sporobolus pumilus (Spartina patens) in foreground (NJ pic)

Sporobolus alterniflorus is more erect in form, and it forms the vast bulk of the vegetation that people associate with marshes as they drive towards the beach. The geometric shapes of their vast stands was quite pleasing to the eye, and I spent some time taking various artistic pics of the scenery.  

Image 7. Geometric stands of S. alterniflorus (S. alterniflora) in the background

I even found flowerheads on some of the nearby specimens. The inflorescences were spike-like, with white anthers dangling out from the flattened spikelets and looking quite grub-like.

Image 8. Inflorescence of S. alterniflorus (S. alterniflora)

Beyond the marsh layer was a forested area, but also pockets of large meadows. This most inner layer is surrounded by the beaches and marshes, and I was astonished to find some species that I would never associate with islands. 

Next to the trail were rows of what I believe were Schizachyrium scoparium (little bluestem), and behind them the beautiful panicles of Panicum virgatum (switchgrass) waved in the breeze. Farther back were dense stands of the invasive Phragmites australis (common reed), which also was present in the high marsh.

Image 9. Meadow layer with a series of grass species

It was an amazing thing to be surrounded by such grasses, when just a few minutes away was marshy waters. But unfortunately, the drier landscape, combined with the disturbance regime due to human activity, has also introduced invasive species to the area. I found dense pockets of Microstegium vimineum (Japanese Stiltgrass) in some of the trails, the silvery lines on the upper surfaces of their leaves the most distinctive sign of their presence.

Image 10. Microstegium vimineum

Nevertheless, I really enjoyed visiting and hiking the short trails in the island, and I loved the structured layering of these major grass species throughout the area.

If you ever visit one of these barrier islands, do keep an eye out for the plants around you. The narrowness of such areas make it possible to go from one ecological region to another with just a short walk.

Monday, October 18, 2021

How an Invasive Grass Secretly Spread and Eluded Eradication

Tiny spikelets of Oplismenus undulatifolus

The insidious invader first came to light in 1996, in Patapsco State Park in Maryland, and by 2004 it had leapt into the next state and was discovered infesting a large area in Virginia's Shenandoah National Park. Efforts to eradicate it while it had a limited distribution began in earnest, but fifteen years later, it had spread to thousand of hectares in Maryland, Virginia, and even one spot in Pennsylvania. 

The distinctive wavy leaves of O.undulatifolius

The ability of Oplismenus undulatifolius (Wavyleaf Basketgrass) to defeat all efforts to halt its advance was likely due to several factors.  The first is its long lived perennial nature, an attribute different than a congener, the also invasive Microstegium vimineum (Stiltgrass). This allows it to push up from thick litter every year using well developed roots, unlike the latter, which has to germinate from more vulnerable seed every year.

The second factor is the ability of this understory species to thrive in very dim light. One study found that it could still grow in as low as 2-11 mols m2 per day of light. This allows it to exist within the forest interiors, and thus escape the attention of many biologists and others who usually do not wander far from trails. 

Stigma of Wavyleaf Basketgrass

The third factor which allowed Wavyleaf Basketgrass to thwart attempts to contain and eliminate it was a characteristic that was in full display when I chanced upon a small cluster of this invader near Shenandoah National Park yesterday.

I saw what looked to be tiny beads strung along 5 to 10 cm spikes that shot out from the masses of wavy leaves. Each bead was perhaps 1 or 2 mm in diameter, with sharp awns projecting from them.

When I used my macro lens to view the beads, I suddenly realized these were flower and seedheads!

Awns with sticky liquid

Under the macro lens, the spikelets of this grass looked like alien spaceships, with the awns decorated with beads of liquid.

It turns out that O. undulatifolius disperses its seeds using unwitting animals, with the sticky liquid enabling them to attach to the fur or shoes and socks of passing fauna. Wavyleaf Basketgrass is a prolific producer of these sticky seeds, with dense stands developing more than 6000 seeds per square meter every year. It is such a profligate invader that Prof. Vanessa Beauchamp found that a dog running through this grass could pick up 12000 or more seeds on its fur! People are also used as vehicles for dispersal, with one study showing that around 800 seeds adhered to fleece within 30 seconds, while even denim pulled in around 300 seeds within the same timespan!


Given all these attributes, it is certainly understandable why all attempts to eradicate the invasive grass have so far proven futile. But if you are out hiking and find this, then be sure to report the find in order for us to at least contain it.


References

Beauchamp, Vanessa B.; Koontz, Stephanie M.; Suss, Christine; Hawkins, Chad; Kyde, Kerrie L.; Schnase, John L. (2013). "An introduction to Oplismenus undulatifolius(Ard.) Roem. & Schult. (wavyleaf basketgrass), a recent invader in Mid-Atlantic forest understories". The Journal of the Torrey Botanical Society. 140 (4): 391–413.

Peterson, P.M., E.E. Terrell, E.C. Uebel, C.A. Davis, H. Scholz, and R.J. Soreng. 1999. (Scientific Note) Oplismenus hirtellus subspecies undulatifolius, A new record for North America. Castanea 64:201-202.

Thursday, October 7, 2021

Elymus hystrix: Spiky Angel


This is probably one grass species that you will easily recognize.

It has amazing looking spikelets that look sharp and pointy - perhaps sharp enough to to prick your thumb, though I did not try.

I encountered it during a NJ hike in July 2020, in a somewhat shaded location next to a river.

I later identified it as Elymus hystrix, and it is a species that likes filtered light and nearby water, which describes exactly the location of the specimen that I found.

E. hystrix is called Eastern bottlebrush, due to the overall shape of its inflorescence. Its specific epithet is from the Greek hystrix, which means "hedgehog", an apt moniker given the spiny looking spikelets. It's a perennial grass and can self-pollinate, which I assume is a trait that is sometimes useful when one is separated from the rest of the population.

The specimens I encountered were huddled amongst the other vegetation, just native plants blending in with the crowd. It was such a difference from (for example) Taeniatherum caput-medusae (medusahead grass) or Imperata cylindrica (Cogon grass), both of which exist in dense clusters that exclude most other species. 

Cogon grass existing in very dense clusters

I admit I like it. It's a clean looking native species with an unusual and readily identifiable inflorescence (always a boon to a noobie like me who has trouble identifying graminoids) and perhaps I'll see it again during hikes in the Shenandoah area this month.



Tuesday, October 5, 2021

What is the most bio diverse place on the planet Earth?

The grass Cenchrus setaceus (Pennisetum setaceum) spikelets

If you ask people which place in the world has the most species in a given area, many of them would probably pick the tropical rainforests.

The concept of the tropical rainforests as being the most diverse ecological environment on Earth has been drummed into us continuously by popular culture, but it turns out that answer is only partially correct.

By Dukeabruzzi - Own work, CC BY-SA 4.0

When researchers counted the number of vascular plant species in different environments around the world, they discovered that the answer to that question depends on how large an area you consider when counting (Wilson et al, 2012).

The most diverse environment in the world when you look at an area greater than 100 m2 is indeed the tropical rainforest. For example, a tropical rainforest in Ecuador had 942 species of vascular plants living in 1 hectare (10,000 m2) of land.

But when you look at smaller areas, the answer turns out to be different. When they counted the number of species of vascular plants in an area smaller than 100 m2, they found out that the most diverse environments are actually temperate grasslands. For example, a mountain grassland in Argentina had an absolutely amazing 89 vascular plant species packed into a single square meter (click table below)! 

I'll admit that actually blew my mind because I can't imagine fitting almost 100 plant species (not individual plants, but different species!) into an area only half the size of a small twin bed.

(Wilson et al, 2012)

But the even more amazing thing is that a new study seems to indicate that researchers may be undercounting the total number of species in grasslands if they only look at aboveground structures, and that total species richness could be up to 65% higher (Rucinska et al, 2021).

In the end, the studies indicate grasslands were the most diverse environments at all the smaller scales that the researchers examined, and it and the tropical rainforests can thus be doubly crowned the most biodiverse places on planet Earth.

Given this fact, my hope is that people come to realize that our ancient and "old growth" grasslands can be just as diverse and species rich as rainforests, and must therefore be just as cherished and protected.

Spikelets of the native grass Little Bluestem (Schizachyrium scoparium)

References:

Anna Rucinska, Sebastian Swierszcz, Marcin Nobis, Szymon Zubek, Maja Boczkowska, Marcin Olszak, Jan G. Kosinski, Sylwia Nowak, Arkadiusz Nowak (2021).
Is it possible to understand a book missing a quarter of the letters? Unveiling the belowground species richness of grasslands. Agriculture, Ecosystems & Environment, 2021, 107683, ISSN 0167-8809


Wilson, J. Bastow; Peet, Robert K.; Dengler, Jürgen; Pärtel, Meelis (1 August 2012). "Plant species richness: the world records". Journal of Vegetation Science. 23 (4): 796–802.